1. Field of the Invention
The present invention relates to a collapsible pallet and related products and more specifically relates to a unique pallet which is formed from folded sheet material whereby pallet channels are established. Supporting inserts are included in the pallet channels and spanning beams are passed through slots at right angles to the channels to enhance the structural support. The related products include pallets with walls extending upward to form containers such as boxes and trays as well as containers wherein the walls extend downwardly and are folded in a predescribed fashion to create channels of the type set forth in the present invention.
2. Prior Art Statement
Pallets have been used for many years for supporting boxes, crates, barrels and other types of packaging for stacked transport and have typically been constructed of wooden lattice arrangments involving parallel boards mounted horizontally on vertical slats or runners at right angles thereto. Over the past few years, developments have been made to create substitutes or partial substitutes for wood in the construction of pallets. This led to not only changes in the construction materials, but also to modifications in the actual pallet designs themselves. While the prior art is replete with teachings which show many variations on the pallet, including cardboard pallets with some types of folds or supports, to date, no prior art teaching has set forth the particular advantages or particular design of the present invention. The following prior art patents are representative of the pallet and palletized container art:
U.S. Pat. No. 2,944,296 to J. P. Hamilton, describes a pallet consisting of a plurality of channels which are made from folded cardboard or the like and which include wooden slats inserted through slots to create the basic pallet lattice structure. However, the Hamilton type pallet is made of independent channels which are somewhat free floating relative to one another, are not prealigned with respect to the distances between each of the channels nor are they necessarily assured of being kept in parallel. Additionally, when the Hamilton type pallet is in use, it is possible for movement of the channels relative to one another whereby some risk might be created regarding weight loads at the ends of the flats where the channel may have been accidently or through movement pushed under the weight and tipping may occur. Thus, the Hamilton pallet substantially reduces the amount of wood involved but increases the complexity of the arrangement and, more significantly, creates risks which are not inherent in the nailed pallet design which is conventionally used.
U.S. Pat. No. 2,444,183 to Cahners describes a fiber board portable platform which includes the formation of channels from folded cardboard and their interlocked relationship including the use of cross members to enhance support, which cross members are located within the channels themselves. While the fiberboard platform of Cahners does allow for formation out of fiberboard without the need for any nailing, there are channels formed in one direction and no support members at right angles thereto other than the flat cardboard surfaces. Thus, in a Cahners type fiberboard portable platform, if the weight load is shifted onto, for example, two out of three of the channels, when the pallet itself is lifted as with a forklift or is otherwise moved, there is a high likelihood that the cardboard flat surface will fold and the structural integrety of the platform itself will be permanently damaged.
U.S. Pat. No. 4,378,743 to McFarland described a paperboard pallet having interlocked runners. However, this pallet is more like a tray wherein the runners are inserted into the bottom, i.e. are located above and not below the basic horizontal surface and are inserted by the use of blocks located at the bottom of the channels. However, as with the prior art described above, the runners are all in a single direction and only the tray cardboard sidewalls provide for structural support at right angles to the runners. Additionally, the McFarland type pallet runs the risk of forklift motion or other motion actually popping the blocks up through the base and therefore destroying the integrety of the structure itself. Additionally, a folding may occur at points parallel to the runners should the weight be shifted and movement be made in such a manner that force is applied to the pallet areas where there is no significant weight.
U.S. Pat. No. 3,308,772 describes a disposal pallet having channels located on the underside which are basically U-shaped channels formed of sheet material. Again, this type of pallet does not allow for significant structural support at right angles to the parallel channel. Additionally, the pallet channels themselves are hollow and may be subjected to weight which would cause flattening and therefore destruction of the basic integrity of the pallet itself.
U.S. Pat. No. 4,185,565 to Nymoen again describes sheet material type pallets having a base with parallel channels on the underside. In this case, the parallel channels are initially formed by a series of folds from a single undersheet and these are then interlocked with hollow channels formed at the ends of a second base sheet. The result is a pallet which has channels which are hollow but with closed ends. Both the flattening problems as well as the problems of bending at points between the channels are problematic with this type of design.
U.S. Pat. No. 4,091,923 is directed to a combined carton and supporting pallet. This particular design involves a typical cardboard box which has a synthetic pallet with a base in the flap and the flap is simply tucked into the folding flaps of a typical box and then the base is dropped over it. The box is then trned over and rests on sections or channels which are attached to the bottom of the base. This particular type of pallet does not include any structural support at right angles to the runners located on the bottom but is only structurally significant when it is located in place in a particular carton for which it is designed to fit. In other words, the pallet described in this patent is unique to a particular size carton but yet is not an integral part thereof and must be inserted into the carton. If the pallet of this patent is used without being inserted into a carton, it has even less structural integrety than all of the other pallets cited above due to the fact that one of the two top layers would be a free floating flap and the fact that there would be no structural support other than the single piece of cardboard which would bind the runners, at right angles to the runners.
U.S. Pat. No. 2,494,730 to Thursby describes palletized containers which rely upon folded cardboard channels and inserts but again lack any additional structural support other than the cardboard at right angles to the channels.
Thus, the prior art describes many variations on cardboard type pallets and related products but fails to describe any system wherein the channels may be integrally formed from the sheet material base and which include supporting inserts into the channels as well as cross beams located against the underside of the base itself. In other words, the present invention pallets have channels which are supported internally by structural inserts and the channels as well as the base are further structurally supported by beams which run at right angles to the channels, pass through slots in the channels themselves and are pressed against the underside of the base to create significant structural advantages.